Snowman (the Abominable) - born as a beast, Yeti build thread
 

It is happening! My Yeti, who started out as a mere idea, will soon be born into the material world. The delivery will likely take a month or two, but unlike the case of real childbirth, the process is going to be a pleasure.

And his name shall be Snowman (the abominable). Of course. Graphics will be a tribute to the Yeti and to Nepal. Hopefully, since I haven’t painted a lexan body in 25 years.

Before I continue I would like to thank all the people who've helped me out so far. DavidH, magic_yeti, mikemcE, shiftauto and Shinchu - I really appreciate your input.

The discussion that led to this particular set of parts can be found in this thread, but I’ll outline my thinking below for the reader’s convenience. It is probably, hopefully, overbuilt with lots of upgrades for durability. An option would of course be to upgrade things as they brake, but since I live in Sweden delivery from the U.S. often takes two or three weeks and I would just hate to spend my time waiting for parts, instead of driving. I want it tough from the start. I’ve tried not to go way overboard with aluminum parts, since there ought to come a point when too much aluminum adds too much weigth, which in turn would make things break easier. Hopefully I’ve found the right balance. I want function, not baling.

Intended use is mainly as a trailing rig, occasionaly doing some light crawling and some light bashing – simply put: a good all round rig. A holy grail, I know, but hopefully a pretty good shot at finding it.

Motor and ESC
Tekin PRO4 Heavy-Duty Brushless 2-3S 3000kV Motor, 145$. High speed, high torque and more efficient (running cooler at high speeds) than the ROC412, if I got it right. The 2-speed should help give me all the control I will ever need at crawling speds. Check out this thread for an interesting discussion. HH Puller Pro would have been an alternative had I lived in the U.S., but I don’t. Ended up too expensive.Castle Creations Mamba X Sensored 25.2V WP ESC, 145$. Seems to be the golden standard. This review by rcdriver is a good read
4mm bullet connectors, three sets, 12$. For connecting motor to ESC. Was about to miss out on this one.Tekin 12AWG wire, 10$<o:p>XT60 Connectors, 7$. I have Deans on my other car and am not very satisfied with them. They get stuck to easily. Time to change to something else and lots of people seem to be very satisfied with XT60. Since I drive on my own borrowing batteries is not an issue. Should it ever be, I'll make a Deans - XT60 adapter.

Steering servo
Xpert 7701, 99$. Plenty strong (380 oz-in @ 7,4V; 485 @8,4)and waterproof according to IP67
Castle Creations BEC, since the receiver only handles 6,0V and I want to run the servo at 7,0 or 8,4 V.
Bypass adapter, to power the steering servo directly from the battery, bypassing the receiver. Should save me some soldering, as far as I can understand.

Radio and receiver
FlySky GT3B. I have one already. Certainly good enough. Since the receiver only handles 6,0V, I am getting a BEC to power the steering servo.

Servo for 2-speed transmission
Savox 0231MG, 37$. Waterproof, strong enough and popular in this application.
servo reverser, 9$. Since transmission and aux-wire will run in parallell. Without this one, it seems as if crawler mode will be enabled in 2nd gear and race mode in 1st.

Re: Snowman (the Abominable) - born as a beast, Yeti build thread
 

Aluminum parts from STRC.
Steering bellcrank set, 42$. To tighten up steering a bit
Front skid plate, 18$
Front caster block, 21$
Steering knuckles, 27$
Rear upper shock mount plate, 7$. Maybe not necessary, but cheap and doesn't add to many grams.

Axial aluminum parts
Machined Adjustable Motor mount, 30$
Servo horn 25T, 14$

Rear end stuff
MIP X-Duty Rear C-Drive Kit, 34$. Seems to be a popular upgrade, when the original breaks.
SSD wide rear axle, 110$. Probably overkill, but as I said before, I hate waiting for parts and want it tough from the start.
SSD rear trailing arms, 35$. As pointed out elsewhere, the rod ends define a break point and are cheap to replace. Therefore not Vanquish.
SSD Titanium rear upper links, 18$. Stainless steel might be better according to some, but these weigh less.
SSD rod ends, 4$. To have in my pocket.


Wheels and tires
SSD Proline wheels, 108$. Durable, looking good and cheaper than Vanquish alternative.
Proline Hyrax tires, 60$. Should provide plenty of traction. People seem to be very happy with these.
CI Double Deuces foams, soft and medium for front and back respectively, 34$. As far as I can understand, this is the s**t when it comes to foams.

Gears, bits, bobs and pieces
Axial 2-speed transmission, 95$. For versatility on and off the trail. Ordered from TowerHobbies, which makes it about the same price as the SSD version. If I use the high speed optional gearing, difference between 1st and 2nd gear is about the same (only slightly smaller, should not be noticable) as with the SSD transmission.
Stainless steel screws from RC Schrauben, ~45$. Included screws rusts far too easily, according to DavidH. Might as well use stainless from the start, and in addition the set includes 50% more than needed so that I won't have to buy individual replacements.
RPM front A-arms, 15$. Which will be fitted some 3/16 Stainless steel tubes for strengthening the hinge pins.
500.000 Cst diff fluid for the front diff. According to DavidH this should keep the diff functionally locked, but allow for movement during crashes. Makes sense.

I think that's about it. Should keep me occupied for a while.

Re: Snowman (the Abominable) - born as a beast, Yeti build thread
 

Placeholder.

Re: Snowman (the Abominable) - born as a beast, Yeti build thread
 

Paws are showing! Proline Hyrax mounted on SSD wheels with CI double douces foams. Such beauty! Loctite on all screws, everything fit perfectly. Nice beginning of my build. https://uploads.tapatalk-cdn.com/201...fa9bd8336b.jpg

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Re: Snowman (the Abominable) - born as a beast, Yeti build thread
 

I think I would go for XT90's, just to be sure as for amp draw with this motor and ESC...

Nice list for the rest [emoji106]

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Re: Snowman (the Abominable) - born as a beast, Yeti build thread
 

A couple of XT60 connectors are already lying on my desk. I can't remember why I chose XT60 over XT90, but I did read up on it and am pretty sure they will do fine.

Nice, and expensive. But cost per hour of fun will still be cheaper than going to cinema. Or gambling. Or a lot of other things.

Re: Snowman (the Abominable) - born as a beast, Yeti build thread
 

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Re: Snowman (the Abominable) - born as a beast, Yeti build thread
 

LOL

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Re: Snowman (the Abominable) - born as a beast, Yeti build thread
 

To be more accurate, on loose surfaces 500K will drive like the front diff is locked, but on more challenging terrain there will be slip; regardless, it is a good place to start. If you want to test out the low gear with some crawling/climbing, put a 200-500g lump of lead in the front bumper to ballast the nose down, to help in keeping the front tires in contact with the ground.

Re: Snowman (the Abominable) - born as a beast, Yeti build thread
 

I love building wheels and tires first. And you made a good choice with those.

Re: Snowman (the Abominable) - born as a beast, Yeti build thread
 

I got my kit today and am very much looking forward to start putting it together this weekend. Looking through it I found this, and I don't really know what it is for. Masking the headlights when painting I guess? And masking a really ugly axial logo? Please educate me on the subject. https://uploads.tapatalk-cdn.com/201...bb39087fc4.jpg

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Re: Snowman (the Abominable) - born as a beast, Yeti build thread
 

yes masking tape. only i used from was the part for the front lights. to keep the body clear for the lights.
in this post is a little vid of my light installation: http://www.rccrawler.com/forum/axial...ml#post5674189
have fun building the snowman"thumbsup"

just a hint if you screw into plastic use a little dip grease on the screw and loctide if screwing into metal :)

Re: Snowman (the Abominable) - born as a beast, Yeti build thread
 

Thanks magic_yeti! What's dip grease? I suppose you mean diff grease? Does screws lock better into the plastic then? I've got loctite, used it when assembling the SSD wheels.

Re: Snowman (the Abominable) - born as a beast, Yeti build thread
 

no the opposite on plastic. if you screw into plastic special the first time it's producing heat cutting the tread into plastic afterwarts the plastic cools down and shrinks, using a little dip grease reduces the heat. so if you have to take the screw out it's not so tide as without grease and the possibility to strip the screw is reduced. didn't do this on mine and striped a few screw hassel to get them out some i had to drill out. i use silicon grease for this but any should work.

Re: Snowman (the Abominable) - born as a beast, Yeti build thread
 

Good to know, intetesting. I'll dip my ss screws from RC Schrauben in diff grease then. Or loctite, when appropriate.

Re: Snowman (the Abominable) - born as a beast, Yeti build thread
 

Interesting. I've never heard of dip grease before.

Re: Snowman (the Abominable) - born as a beast, Yeti build thread
 

Got both stock and RPM A-ARMS sleeved. 8$ and thirty minutes, thanks for the tip. Only one problem can be forseen: the blue RPM stickers won't look good on a blue body. https://uploads.tapatalk-cdn.com/201...a249497823.jpg

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Re: Snowman (the Abominable) - born as a beast, Yeti build thread
 

Unforseen problem: stock outer hinge pins are too short for the RPM A-arms. Sock arms are therefore installed and longer hinge pins, M3 x 40mm should do it, will be ordered. Together with some green slime for shock building.

Re: Snowman (the Abominable) - born as a beast, Yeti build thread
 

how about some pics of your progress :)
may be you find some screws that fit the rpm in the set.

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Re: Snowman (the Abominable) - born as a beast, Yeti build thread
 

Ain't much to it yet, but here's progress so far.https://uploads.tapatalk-cdn.com/201...e7939426d3.jpg



https://uploads.tapatalk-cdn.com/201...305b849861.jpg

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Re: Snowman (the Abominable) - born as a beast, Yeti build thread
 

I've been thinking about building a yeti and your build is giving me the itch. Keep it coming.

Re: Snowman (the Abominable) - born as a beast, Yeti build thread
 

Very slow progress. I got the RPM A-arms on, as well as the steering linkage. Here are some pics, just to keep it itching. https://uploads.tapatalk-cdn.com/201...4183fc7daf.jpg


https://uploads.tapatalk-cdn.com/201...38cc223412.jpg

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Re: Snowman (the Abominable) - born as a beast, Yeti build thread
 

I've spent the evening soldering (first time in 25 years!) and trying to get the wiring right, but I just can't figure it all out. This is what I've got:

ESC (Mamba X)
BEC
Rx bypass adapter
Y-harness with servo reverser
Steering servo
Servo for gearbox

BEC goes into the Rx bypass adapter, which in turn is connected to the steering servo and the receiver, right? And then I use Castle link via the ESC to set the BEC output voltage, right again? Do I need to have a battery connected to program the ESC and BEC?

The Y harness has two female contacts, I guess the Aux wire goes into one and the gearbox servo goes into the other? The male then goes into Rx channel 3? I then use Castle link to set the the aux wire to switch between rock racer and crawler mode as I change between second and first gear. Should the servo be reversed, so that crawler mode is enabled in high gear, I just switch places of the aux-wire and servo contacts going into the Y harness/servo reverser?

Bypass adapter from steering servo then goes into rx channel 1?
Brown-red-yellow wire from ESC goes into rx channel 2?
Wire from Y-harness goes into rx channel 3?
One slot (top one, called VCC) on rx is left empty?

Please give me a helping hand, I feel rather lost.

On the slightly more practical side, where to stuff away all those wires? And where to put the on/off-switch?

Re: Snowman (the Abominable) - born as a beast, Yeti build thread
 

I've not seen the pinout on this adapter, but that sounds right.
You don't need the battery connected for programming of the esc or bec.
Sounds right.
You would have already done this previously when you set the mamba's bec voltage, updated the firmware (if required), and set the aux wire for the rock racer/crawler mode switch.
No, you connect the esc to the rx, then set the endpoints to engage/disengage the rock race/crawler mode to your liking, reversing the servo direction at the tx to get the switch working in the direction you want (up for high gear, down for low?) and then connect the servo using the (reversing) y-harness.... then if the servo does not move in the 'right' direction to engage the hi/lo gear to match the esc you then remove the (reversing) y-harness and put in a 'plain' y-harness.

Lastly, you install the servo horn and linkage to the 2-speed, so that the shift lever moves to fully engage the gears but is not stressed at the endpoints.
I'd need to see the pinout on the connectors.
yes.
yes.
yes.
I managed to get rx and castle bec and the spare wire into the fuel cell. I had to cut a larger horizontal slot to accommodate the wires and add some weatherstripping to keep the crap out.

I have a waterproof rx and I made the castle bec waterproof myself.

Re: Snowman (the Abominable) - born as a beast, Yeti build thread
 

Did you add a spacer under the spring?

Re: Snowman (the Abominable) - born as a beast, Yeti build thread
 

for the on/off switch is a holder on the back of the chassis, beside the upper link mounts.
i put all extra electronic in the fuel cell, as davidh mentioned. very crowdy in there.

correct "thumbsup"

no is powered by the usb port over castle link

you never forget how to solder if you have learned it once, like riding a bike:mrgreen:

Re: Snowman (the Abominable) - born as a beast, Yeti build thread
 

I don't recall burning myself so often when riding my bike. :D

Re: Snowman (the Abominable) - born as a beast, Yeti build thread
 

Thanks a lot for helping me get this sorted! Seems as if I knew what to do (or rather just made some good guesses) , but didn't know that I knew, and then it's no real use knowing anyway.

Here's the Rx bypass and planned wiring to and from it.
https://uploads.tapatalk-cdn.com/201...85f0dbb82a.jpg

I'll leave the BEC outside the rx-box and waterproof it by squirting some silicone into it. That ought to make it at the very least splash proof and that should be enough. I plan to drive Snowman as a car, not a submarine.

Re: Snowman (the Abominable) - born as a beast, Yeti build thread
 

be carefully with silicon and electronics, if not special for electronics some silicon can destroy your electronics. your wiring is correct "thumbsup" in the pic.
i use balistol seal spray (liquid PVC) from hornbach (german homedepot) and plastidip (liquid rubber) to waterproof.

Re: Snowman (the Abominable) - born as a beast, Yeti build thread
 

Didn't know silicone can destroy electronics. I'll go hunting for liquid PVC instead. Or just use a balloon.

Re: Snowman (the Abominable) - born as a beast, Yeti build thread
 

Put a couple coats of this on and you’re good to go man.
https://uploads.tapatalk-cdn.com/201...75816e2488.jpg

Cheers!!
NastyMan


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Re: Snowman (the Abominable) - born as a beast, Yeti build thread
 

Looks good. Use it as you have it labeled.
I never fully submerse my cars but I find that snow can be just as bad, the way the snow clings to the relatively warm electronics, and the water still gets in there.

Back in the 80s I learned that silicone rubber is not a great water-proofing substance. While it does block liquid water, it can pass water vapour, and can be acidic; back when we needed big antennas on the (real 1:1) cars and truck radios, it was found that the metal would rust around and under the silicone rubber sealant.

Link

What you want to apply to the electronics is a conformal coating, such as this:

https://www.rpelectronics.com/Media/400/422b-55ml.jpg

https://www.rpelectronics.com/422b-5...quid-55ml.html

I've also used a squirt of Fluid Film inside of a bec or servo, then sealed the seams with liquid tape, or larger openings with Goop. I would not rely on plasti dip or liquid tape by itself, as I consider it to be fragile. Goop is removable if one is careful, unlike silicone rubber.

Re: Snowman (the Abominable) - born as a beast, Yeti build thread
 

Another night spent soldering and trying to get a semblance of order among all the wires. In the end I think it turned out alright. I led all the wires under the receiver to the back right hand corner of the chassis, and then used a fair amount of heat shrink tubing to bundle up excess lengths of wire. The switch was just taped to the side of the ESC.
https://uploads.tapatalk-cdn.com/201...380ba67425.jpg

https://uploads.tapatalk-cdn.com/201...339541e3ce.jpg

https://uploads.tapatalk-cdn.com/201...d388a75fc4.jpg

And with all that done, I just found out that my FlySky tx didn't come with a battery, so I'll have to order one in order to try it all out. Frustrating. Certainly lots of things ordered to get this beast running.

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Re: Snowman (the Abominable) - born as a beast, Yeti build thread
 

the gt3b tx uses normal batteries you can get in normal stores. but could be upgraded with a 3s lipo with some soldering:mrgreen: i use a zippy compact 1500mAh 3s 25c from Hobbyking. fits perfectly if the battery tray is removed.

https://uploads.tapatalk-cdn.com/201...250bfc17da.jpg

Re: Snowman (the Abominable) - born as a beast, Yeti build thread
 

It's a GT3C, not a B, and that one needs a specific 800 mAh LiPo battery. Well, there are things to build while waiting, so it won't really delay finishing.

Re: Snowman (the Abominable) - born as a beast, Yeti build thread
 

yes the c uses a lipo, but it should be included if you purchase it. I would email the vendor why it was not incl. in your package.
Nice and clean wiring, reminds me that my wiring is still test mode and has to be cleaned up. right now it's a mess.

Re: Snowman (the Abominable) - born as a beast, Yeti build thread
 

Glad you like my wiring, all the more reason to be satisfied myself. Concerning the battery I mailed the vendor yesterday, so I hope it will be sorted.

Re: Snowman (the Abominable) - born as a beast, Yeti build thread
 

The roof is ready, with a portrait of the Abominable Snowman himself.

https://uploads.tapatalk-cdn.com/201...9ffbf06055.jpg

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Re: Snowman (the Abominable) - born as a beast, Yeti build thread
 

9And now I've run into a most unexpected problem. In the kit there was two left side 4 link mounts, and no right side one. Annoying. Both were lying loose in their plastic bag. I have written Axial and hope they'll send me a new parts tree. Or a pair of machined mounts.

What's the word on Axial customer support?

https://uploads.tapatalk-cdn.com/201...8753368509.jpg

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Re: Snowman (the Abominable) - born as a beast, Yeti build thread
 

If they don't set you up i can send you my one, but will take till next weekend, if've changed to gpm alloy ones.
https://www.asiatees.com/display?Axi...Yeti&id=103331
they also came in blue 8)